I. Field of the Invention
The present invention generally relates to the field of electronic data processing and, more particularly, to computer systems and methods for operating a computer system for updating structured data.
II. Background Information
WO 02/061612 A2 and WO 02/061613 A2 disclose a data structure for information systems and a database system with an optimized query option, respectively. These documents describe enhanced data structures on the basis of which a database system containing structured data can be operated more efficiently. Particularly, such an improved database system contains a new main memory based search engine for structured data, hereinafter referred to as a “speed search engine.” The data resides in data structures optimized for read accesses in main memory. The data is replicated from a data source, such as a relational database management system. The replication process includes the extraction of the data from the data source and loading the data into the speed search engine, including the meta data. This process may be time consuming. It is not advantageous to repeat such an initial load regularly, for example, to obtain a later version of the data.
The role of the speed search engine is that of a secondary data storage, whereas the database is still the master and also responsible for the persistence of the data. The speed search engine allows for fast access to the data during production operation and provides full index behaviour. This means that expensive select statements due to missing or incorrect indexes do not exist, unlike in the case of a database. However, the speed search engine is not responsible for the persistence of the data. This task is still left to the database, while the speed search engine holds the data persistently in flat files in order to be able to recover using these files in case of emergency (for example, after a power failure). This avoids a new initial load of the speed search engine. However, no backups are created for these files, unlike in the case of database files. If a disk crashes and data is lost within the speed search engine, then a new initial load is necessary.
WO 02/061612 A2 and WO 02/061613 A2, both published on Aug. 8, 2002, disclose a data structure for information systems and a database system with an optimized query option, respectively. These documents describe enhanced data structures on the basis of which a database system containing structured data can be operated more efficiently. Particularly, such an improved database system contains a new main memory based search engine for structured data, hereinafter referred to as a “speed search engine.” The data resides in data structures optimized for read accesses in main memory. The data is replicated from a data source, such as a relational database management system. The replication process includes the extraction of the data from the data source and loading the data into the speed search engine, including the meta data. This process may be time consuming. It is not advantageous to repeat such an initial load regularly, for example, to obtain a later version of the data.
WO 02/095632 A2 refers to a synchronous change data capture system and methodology in which for each statement of a transaction, a transaction identifier that uniquely identifies each transaction is recorded along with the change data. When the transaction is committed, the transaction identifier and a system change number for the commit is recorded in a transaction table. This method is not very time efficient because of the basic necessity to assign an individual transaction identifier to each transaction.
The document “Extracting Delta for Incremental Data Warehouse Maintenance,” by Ram P. et al., Data Engineering, 2000. Proceedings. 16th International Conference on San Diego, Calif., USA 29, Feb.-March 2000, Los Alamitos, Calif., USA, IEEE Comput. Society US, 29, Feb. 2000 (2000-02-29), pages 220-229, XP010378715, ISBN: 0-7695-0506-6describes and analyzes several methods for the extraction of changes to data at a source system, including time stamps, differential snapshots, triggers, and archive logs.
WO 02/095632 A2, published on Nov. 28, 2002, refers to a synchronous change data capture system and methodology in which for each statement of a transaction, a transaction identifier that uniquely identifies each transaction is recorded along with the change data. When the transaction is committed, the transaction identifier and a system change number for the commit is recorded in a transaction table. This method is not very time efficient because of the basic necessity to assign an individual transaction identifier to each transaction.
One problem is to specify a mechanism such that the application can provide changes to a speed search engine and that the speed search engine can ensure transactional consistency of its data.